The present invention relates to a thermoelectric conversion device utilizing the Seebeck effect in which power is generated from the temperature difference between a hot junction and a cold junction, and to a method of manufacturing the same.
Conventionally, a thermoelectric conversion device has been used as a power supply or an auxiliary power supply of an electronic device, a temperature sensor or an infrared ray sensor. For example, the thermoelectric conversion device disclosed in Japanese Laid-Open Patent Publication No. 2002-50801 includes a plurality of series-connected thermocouples. Each thermocouple is L-shaped and has a parallel section parallel to a substrate and a perpendicular section perpendicular to the substrate.
In the thermoelectric conversion device of the above-mentioned publication, a glass layer is formed on the substrate, and the plurality of thermocouples, each including a first junction and a second junction, are formed on the glass layer. The first junction is formed on a first end of the thermocouple and the second junction on a second end of the thermocouple. The glass layer, except for the region corresponding to the first junction of each of the thermocouples, is removed, and thus each of the thermocouples is held like a cantilever. Subsequently, each of the thermocouples besides the first junction region (the parallel section) is bent perpendicular to the substrate to form a perpendicular section.
Next, in each of the thermocouples, the region except for the distal end of the perpendicular section (second junction) is filled with resist. Then, for example, semiconductor or metal is deposited on the resist to form a top plate. Afterwards, the resist is removed. As a result, the second junction and the top plate are adhered together. By adhering the second junction and the top plate, heat is smoothly transferred between the second junction and the top plate. This increases the thermoelectric conversion of the thermoelectric conversion device.
However, it is troublesome to form each of the plurality of thermocouples in the conventional thermoelectric conversion device since each of the thermocouples must be bent individually in order to form the parallel section and the perpendicular section. Furthermore, if the height of the second junction of each perpendicular section is not equal, there is a possibility that each of the second junctions and the top plate do not adhere securely. This would affect the thermoelectric conversion between the second junctions and the top plate.